Transcript Best management practices for nitrogen in intensive
The Carbon Farming Initiative and Agricultural Emissions
This presentation was prepared by the University of Melbourne for the Regional Landcare Facilitator training funded through the Australian Government’s Carbon Farming Initiative Communications Program
PART 1: INTRODUCTION TO THE SCIENCE OF AGRICULTURAL EMISSIONS AND SINKS
This presentation provides a basic understanding of the soil, plant and animal carbon and nitrogen cycles
The Carbon cycle
http://www.davidsuzuki.org/files/CCcarboncycle.GIF
C-stocks in Pg (Gt), C-fluxes in Pg yr -1 ; Pg = 10 15 g = 1 Gt (gigatonne) • Large carbon pools, relatively small fluxes between pools • More carbon emissions than carbon uptake fossil fuel emissions • Increase carbon sinks – increase terrestrial plant or soil sinks
Global forest distribution
www.fao.org/forestry
Sources of global CO 2 emissions
10 8 6 4 2 Fossil fuel Land use change 1960 1970 1980 1990 2000 2010 Le Quéré et al. 2009, Nature-Geoscience; Data: CDIAC, FAO, Woods Hole Research Center 2009 12% of total anthropogenic emissions Slide courtesy of J. Canadell, Global Carbon Project
Carbon stocks and sequestration Carbon stock/pools
How much C at one point in time
Aboveground biomass
Leaves, stem, branches
Litter & coarse woody debris Below ground biomass
Coarse roots, fine roots, microbes
Soil carbon
Stable and labile fractions
Carbon sequestration
Change of C stock over time
NPP
Net primary productivity
14 12 NPP blowground Forests produce most of the terrestrial carbon 10 8 6 4 2 Tropical forest are the most productive Crops produce mainly aboveground NPP consequences for soil C 0 -2 0.5 2.6 8.1 21.9 14.9 7.0 3.5 4.1 NPP Pg C yr -1 Tundr a Boreal For es t per at e For Tr es t opic Tem al Fores Tr opic t al sav anna p gr as sland Tem D es er ts C rops Saugier (2001) IN: Terrestrial Global Productivity
The Carbon cycle
• Human activity greatly influences the global C cycle • The sink capacity of natural CO 2 sinks is decreasing, leading to increased atmospheric CO 2 • Forest ecosystems are the greatest carbon sink in the terrestrial biosphere • Globally, soils store more C than biomass • The capacity of an ecosystem to store C is determined by the balance of C uptake (photosynthesis) and C loss (respiration)